(Applicant's Abstract) We propose to establish an NIH-supported research training program in Immunohematology and Transfusion Medicine designed to take MDs and MD/PhDs, who have fully completed their clinical training in these disciplines, and provide them with the tools to become productive physician-scientists with an abiding interest in basic science and translational research in these relatively underrepresented investigative areas. We believe that these biomedical scientists should be trained in an environment that emphasizes basic biological processes and which simultaneously provides continuous didactic exposure to those state-of-the-art investigative issues which are relatively unique to immunohernatology and transfusion medicine, e.g., transfusion-induced immunomodulation, cellular alteration and apoptosis during ex vivo storage, cell engineering pretransfusion, and allo- and auto- immunity to circulating cells and plasma proteins. Our interdisciplinary and multi-departmental faculty include 21 investigators (19 senior and 2 junior, including MDs, MD/PhDs and PhDs) who have a long history of collaborative publications, trainees and grants and whose laboratories are very experienced in the simultaneous training of post-doctoral PhDs, post doctoral MDs and pre-doctoral PhD candidates. We have the educational philosophy that trainees in this program must have their core experience at the bench, that they require carefully crafted training and career guidance by an individualized trainee committee somewhat analogous to a pre-doctoral thesis committee, and that we must provide ongoing venues for them to interact on a one-to-one basis with additional internationally recognized investigator's in immunohematology and transfusion who are from other institutions. In the 1st year of the grant we are requesting support for one post-doctoral position and thereafter for support of 2 post-doctoral positions each year. We expect that MD trainees will require 2-3 years of training at this level before moving to a K-award equivalent and MD/PhDs 1-2 years with one new trainee added to the program each year. We have had past successful experience training exactly the same type of individuals we propose for this T32 but using mechanisms of support other than a T32 (individual NRSAs, research fellowships from foundations and the like). Those individuals have all gone on to successful academic careers. We believe strongly that an institutional T32 would provide a markedly enhanced, coordinated and formalized training experience for this type of clinician-scientist and provide a smoother pathway for these individuals to move to the next level of independence and eventually comprise the next generation of clinician-scientists who can bridge the gap between fundamental research and clinical need in immunohematology and transfusion.